C++ – Clang on Windows

c++clangllvmmingwwindows

First of all, I've followed "Getting Started: Building and Running Clang". In particular, I've built it according to "Using Visual Studio" section. In other words, I've built it using Visual Studio 2010.

Secondly, I've manually set include and library paths to MinGW distribution:

enter image description here

The simple program I'm trying to compile:

#include <iostream>
using namespace std;

int main() {
    cout << "Hello, World!" << endl;
    return 0;
}

I get the following feedback from the compiler:

In file included from C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\iostream:39:
In file included from C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\ostream:39:
In file included from C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\ios:38:
In file included from C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\iosfwd:41:
In file included from C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\bits/postypes.h:41:
C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\cwchar:144:11: error: no member named 'fgetws' in the global namespace
  using ::fgetws;
        ~~^
C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\cwchar:146:11: error: no member named 'fputws' in the global namespace
  using ::fputws;
        ~~^
C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\cwchar:150:11: error: no member named 'getwc' in the global namespace
  using ::getwc;
        ~~^
C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\cwchar:151:11: error: no member named 'getwchar' in the global namespace
  using ::getwchar;
        ~~^
C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\cwchar:156:11: error: no member named 'putwc' in the global namespace
  using ::putwc;
        ~~^
C:\MinGW\lib\gcc\mingw32\4.5.2\include\c++\cwchar:157:11: error: no member named 'putwchar' in the global namespace
  using ::putwchar;
        ~~^
6 errors generated.
Build error occurred, build is stopped
Time consumed: 646  ms.  

The obvious question is – why do I get this?

Additionally, I would like to know more details, and since, Clang website provides extremely brief information – I thought that somebody could clarify the following questions to me:

  1. As far as I understand Clang does not have its own standard library (stdc++ I guess, isn't it?). That's why I have to use MinGW's headers and libraries – am I right?
  2. What is the difference between building Clang with Visual Studio and MinGW?
  3. Do I have to hard-code include paths in clang/lib/Frontend/InitHeaderSearch.cpp or I can skip it and rather specify those paths later through "-I" option as I do in the screenshot above?

Best Solution

If you build Clang with MSVS, it will automatically search the default VS include paths, and pull in those headers. This is the reason the libstdc++ headers are producing errors: they are importing C functions not present in the VS headers. Using Clang for C++ with VS is for now a no-go: you will get link failures due to missing ABI (name mangling and others) functionality in Clang. If you still want to use the MSVS Clang, don't point it to MinGW headers. It will parse the VS headers (including C++), it just will fail to link.


EDIT: I have built a dw2 version of GCC (32-bit only) accompanied by Clang. Exceptions work in this build, and so you can build real C++ stuff with Clang now on Windows. Get version 3.2 here.